The starting system of a diesel generator ensures that the engine starts when you press the start button. It does so by utilizing the electrical energy stored in the battery to operate the starter motor that turns the engine. It later makes the engine rotate until it starts. Without a properly working starting system, a diesel generator can not start, causing it to not supply power when needed. Even a small problem in the battery, wiring, and other equipment can cause the issue of the diesel generator not starting.
Today, through this guide, we will understand the common causes of a diesel generator not starting.
Importance of Proper Circuit Operation
Starting circuit faults usually occur when there is some sort of electrical or connection problem, though the starting circuit plays a vital role in the reliable and smooth operation of diesel generators. A few common causes that are seen the most in such situations are weak or discharged batteries, loose or corroded terminals and wires, and faulty starter motors. Such issues in operation can cause power interruptions, especially in situations where power is needed the most. If the system circuit is in good condition, it improves the overall generator efficiency.
Main Components of the Starting Circuit
The starting circuit consists of several components, and in order to work properly, they must work together smoothly.
Battery
The source of the power for the generator is the battery. It stores the power for the generator, which is especially needed when the generator starts. However, if the battery is weak or discharged, or its terminals are dirty, the generator may not start or turn slowly.
Starter Motor
This is an electric device designed to turn the engine during the starting process. The battery supplies electricity to the starter motor to rotate the engine until it starts running by itself. If the starter motor faces some issues, the engine may turn over slowly or fail to crank entirely.
Starter Relay/Solenoid
The starter relay or solenoid works similarly to an electrical switch. It lets a small current from the start button control the large current needed by the starter motor. If it fails, you may hear a clicking sound, but the engine will not crank.
Control Switch or Start Button
The operator presses this button to start the generator. It sends the signal to activate the starter relay and initiate the starting procedure. However, there might be some issues with the switch; for example, if the switch is faulty or worn out, the generator may not start.
Wiring and Connections
Wires and connectors are utilized in carrying electrical power between the battery, relay, starter motor, and control switch. This will not allow the generator to start smoothly if they are loose, dirty, or damaged.
Common Starting Circuit Faults
Starting circuit faults can be caused by a few common things, including:
Battery-Related Faults
The following are some of the common faults related to batteries:
Low Battery Voltage
Low voltage in the battery means the battery does not contain enough voltage to rotate the engine. This normally happens when the battery is discharged or simply old. In this case, in general, the generator may crank slowly or not start at all.
Battery Terminal Corrosion
Corrosion on battery terminals appears as white or green deposits on the battery posts. This buildup blocks the flow of electricity and can cause starting problems. To fix this, try cleaning the terminals first; it usually solves the issue.
Loose Battery Connections
If the battery connections are loose, it usually prevents the current from flowing properly. This may lead to problems such as clicking sounds or difficulty in cranking. Tightening the connections resolves this situation.
Battery Internal Failure
In some cases, the battery looks normal but has been internally affected, meaning it does not possess the capacity to produce enough power for the generator. This makes the diesel generator fail to start. The battery should be replaced in such conditions.
Starter Motor Faults
Starter motor faults commonly include the following problems:
Starter Motor Not Engaging
This usually happens when the starter motor does not connect with the engine when you try to start. You may notice a clicking sound, while the engine does not rotate. The common cause is a faulty solenoid or internal starter problem.
Slow Cranking
Slow cranking means the engine turns very slowly during starting. This usually happens when the battery is weak or cables are not connected properly. If the engine turns over too slowly, it may fail to start.
Mechanical Seizure
In this case the starter motor gets stuck and cannot run. This is usually caused by dirt, no lubrication, or internal damage. In this case the starter motor will not turn the engine.
Worn Brushes or Armature Issues
Inside the starter motor there are brushes and an armature that help produce rotation. Over time, these parts get old and damaged. This may cause the diesel generator not starting.
Starter Relay/Solenoid Faults
Starter relay faults commonly include the following problems:
Relay Not Energizing
This happens when the starter relay does not activate when you press the start button and is usually caused by a faulty relay or blown fuse.
Solenoid Clicking but Not Cranking
In this case, you can hear a clicking sound from the solenoid, but the engine does not turn, which is commonly caused by weak batteries and loose connections.
Control Circuit Faults
Control circuit faults commonly include the following problems:
Faulty Start Switch
When this happens, pressing the start button does nothing, and this usually happens when the switch gets worn out or is damaged.
Control Panel Failure
The control panel handles the starting command, and if it gets an internal fault or power issue, it may fail to send the start signal.
Faulty Fuses or Breakers
Fuses and breakers are what protect the starting circuit from overload. If it gets fused or if the breaker is tripped, the generator will not start until it is fixed or reset.
Conclusion
The most common causes of problems that may be experienced by a starting circuit of a diesel generator include a low battery, a faulty starter motor, and a damaged wiring system. The early detection of a fault is important to avoid any major repairs. Performing routine maintenance activities like cleaning the terminals, tightening connections, and checking the starting system greatly minimizes the failure risk. Nevertheless, the use of a good-quality diesel generator from renowned manufacturers like Huaquan Power minimizes the chances of the generator not working
